We propose a 3-year project to develop and characterize a mutagenic test system in the frog, Rana pipiens, and to compare the results obtained with those from other mutagenic test systems. In its simplest terms the test system will consist of administration of mutagenic chemical to male frog, recovery of the treated animal's sperm, fertilization of eggs with the sperm, and analysis of the developing embryos for mutagenic changes. We will establish a dose response relationship for both chromosome aberrations and abnormal morphology of developing embryos for the known mutagen, triethylenemelamine (TEM), we will compare somatic vs. gametic chromosomal changes within the same animal, and we will confirm the genetic nature of induced changes by amphibian nuclear transplantation (cloning). The usefulness of mutagenesis screening of androgenetic haploid embryos will be studied. We will test the effects on frogs of different routes of administration of test chemicals. The mutagenic potential of varying classes of known chemical mutagens will be suited.